As an important information carrier and guidance medium in public places, the wayfinding system can help people obtain spatial information from a complex environment in the most intuitive way, guide people to find the right direction, and influence their spatial perception of the environment and overall recognizable intention. Traditional design evaluation and optimization of wayfinding systems are usually performed after the actual installation, which has shortcomings such as long lead time, high cost, and time consumption. VR technology can restore a real scene in an immersive way, build a new evaluation process for the guide system, and provide a new opportunity for the development of the wayfinding system. Accordingly, this study conducts preliminary research and design of the wayfinding system optimization scheme for large public spaces and uses Unity 3D to reproduce the environment of the classroom building virtually, tries out the wayfinding system optimization scheme in the virtual environment, observes the user's moving path, dwell time, etc., compares it with the original wayfinding system to obtain the user's test results, and updates and optimizes the scheme. Compared with the traditional process, the intervention of VR not only provides richer data support for the design and testing of the wayfinding system but also achieves higher-quality design optimization in a shorter period, which contributes to the protection of personal safety and pushes the design of the wayfinding system in the direction of intellectualization and user-friendliness.